Where does Assassin's Creed: Origins fit?

The player takes on the role of a Medjay named Bayek and his wife Aya, as they work to protect the people of the Ptolemaic Kingdom during a time of widespread upheaval: the Pharaoh, Ptolemy XIII, struggles to maintain his rule whilst harboring ambitions of expanding his kingdom; his sister, the recently deposed Queen Cleopatra, begins marshalling loyalist forces to launch a counter-coup against Ptolemy; and frequent incursions into the Kingdom by the Roman Republic under the command of Julius Caesar lead to fears of an imminent invasion.